Topic: UCX II input and output levels

I just purchased a UCX II after having been away from the RME ecosystem for a few years. If I remember correctly, in Totalmix FX you used to be able to set the line input and output levels to either +4 or -10. Now the options seem to be +13 and +19 for line inputs, and +4, +13, and +19 for the outputs.

How do these options correspond to +4dBu or -10? I’m interfacing with balanced pro-level hardware, and in the past I set everything to +4.

Re: UCX II input and output levels

ManaTau80 wrote:

I just purchased a UCX II after having been away from the RME ecosystem for a few years. If I remember correctly, in Totalmix FX you used to be able to set the line input and output levels to either +4 or -10. Now the options seem to be +13 and +19 for line inputs, and +4, +13, and +19 for the outputs.

How do these options correspond to +4dBu or -10? I’m interfacing with balanced pro-level hardware, and in the past I set everything to +4.

See section "20.1 Line" in the manual.

3 (edited by ManaTau80 2023-04-11 11:18:00)

Re: UCX II input and output levels

From what I can understand (which isn’t much), +13 for the outputs is equivalent to the standard +4 setting. Does the same apply for the inputs?

I’m not sure why the standard nomenclature was abandoned, when the rest of my gear is always specified as being +4 or -10. +4 is now +13 and -10 is now +4? That seems wildly confusing.

4 (edited by ramses 2023-04-14 15:50:34)

Re: UCX II input and output levels

There is no confusion, you simply may not be familiar with different line levels. There are "consumer level" line levels for typical consumer devices, as well as different levels for studio equipment, as there is not one common standard.

Here are some general aspects to consider:

  • Reference levels on outputs refer to the output volume, with higher levels being louder.

  • Reference levels on inputs refer to the sensitivity of the input. Higher levels make the input more insensitive to support hotter signal levels and peaks.

It is better to have a little reserve on inputs to prevent overloading. In the digital world, nothing should go higher than 0 dBFS.

Check the manual, as some interfaces may have only 2 reference levels on input, while others have settings for trim gain to add a few dB of more gain/sensitivity. This helps match the input signal, especially for lower signal levels like consumer level.

Regarding UCX II

Analog inputs

  • Input sensitivity is switchable to +19 dBu and +13 dBu

  • Variable gain ranges from 0 to +12 dB

  • To achieve sufficient sensitivity for consumer level, select +13 and add 12 dB of gain. It's good to have enough headroom, but not too much; keep an eye on the input meters' level. For live recording, keep a higher reserve compared to recording known material where the max peak is known

Analog Outputs

  • Switchable between +19 dBu, +13 dBu, and +4 dBu.

  • For connecting active monitors, select +4 dBu to avoid excessive volume.

  • For connecting external devices, start with +4 dBu and check if it results in a satisfactory input level on the device. If it has a volume knob, turn it to about 75-80% and check whether +4 dBu is sufficient. If more volume is needed, select +13 or +19.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13

Re: UCX II input and output levels

Thanks for the response. I understand that RME has decided to list the reference options as “working level + headroom”. On every interface I’ve had in the past — Apogee, Lynx, etc — I was able to simply set +4dBu as the reference level, which often equals 16 db of headroom (4dBu + 16dBu = 20dBu = 0dbfs). This is the case with both Apogee and Lynx, although you can obviously switch the reference level.

For the inputs: are we saying that +19 or +13 = the amount of headroom I have until I hit 0dbfs? Or is the headroom 19-4 and 13-4? In either case, I assume +13dBu or +19dBU = 0dbfs?

For the outputs: is +13 the equivalent to what used to be referenced as +4?

Re: UCX II input and output levels

Let me rephrase this:

For the inputs, I want +4dbu = -18dbfs. With the UCX II, my options are +4dbu = -15dbfs (the +19 setting) or +4dbu = -9dbfs (the +13 setting). In other words, I’ll have either 15 or 9db of headroom. Is this correct?

7 (edited by ramses 2023-04-14 15:52:10)

Re: UCX II input and output levels

The reference levels for this are:
+19 dBu as a reference level with +4 dBu providing a 15 dBu headroom (19-4).
+13 dBu as a reference level with +4 dBu providing a 9 dBu headroom (13-4).

The variable gain ranges from 0 to 12 dB. To achieve a sensitivity of +4 dBu for your inputs, you need to select +13 dBu and set the trim gain to 9 dB. This will provide no headroom, so be sure not to exceed 0 dBFS at the +4 dBu setting (+13 and +9 trim gain).

According to the manual, in chapter 19.1, you can set a reference level of +4 dBu by using +13 dBu and adding 9 dB of gain with the Gain knob in the TotalMix FX channel settings.

If needed, a good unit converter can be found at http://www.sengpielaudio.com/Rechner-db-volt.htm.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13

Re: UCX II input and output levels

This is exactly what I wanted to know. Thank you for the confirmation.